1. Field
The present disclosure relates generally to telecommunications, and more particularly, to telecommunications involving multiple communications networks.
2. Background
Consumer demand for wireless services has led to the development of numerous wireless communication networks. One such network is based on code division multiple access (CDMA) technology which supports wireless voice and data services using spread-spectrum techniques. Spread-spectrum techniques enable high quality service at low cost by efficiently using the available radio frequency (RF) spectrum. As a result, CDMA technology is considered by most to be the next generation of digital wireless communications.
To provide the widest availability of CDMA technology, cost reduction efforts should be employed during implementation. One way to reduce costs is to implement CDMA as an overlay to existing networks such as a Global System for Mobile Communications (GSM). GSM, which has become the defacto standard in Europe and Asia, represents the previous generation of digital wireless communications and utilizes narrowband TDMA to support wireless voice and data services. By implementing CDMA as an overlay to GSM, or other existing systems, reduced cost may be realized because a substantial portion of the existing infrastructure may be used to support CDMA. Within the overlay architecture, the GSM system is augmented to include a CDMA air interface. In this example, a mobile unit may communicate with a GSM core network using either a CDMA or GSM air interface.
The introduction of a CDMA into to a GSM network raises a number of issues. Currently, a GSM mobile unit acquires a connection with a GSM network using provisioning information stored on a removable Subscriber Identity Module (SIM) in the GSM mobile unit. The removable SIM may be installed on any GSM mobile unit, thereby eliminating the need to provision information into a GSM mobile unit every time a new one is purchased by a consumer. Many consumers of GSM products have expressed a certain level of satisfaction with this feature, and therefore, it is desirable to deploy a mobile unit, capable of supporting both a CDMA and GSM air interface, that can accept a SIM from a GSM mobile unit. This will require that certain compatibility issues be addressed to allow the mobile unit to acquire a CDMA wireless network with provisioning information for a GSM wireless network stored on the GSM SIM.